Field of the Invention
The present invention relates to compressors used in heating, ventilation, and air conditioning (HVAC) systems and, more particularly, to a system for managing lubricant levels in tandem compressor assemblies of an HVAC system.
Description of the Related Art
Some heating, ventilation, and air conditioning (HVAC) systems utilize multi-compressor assemblies, such as tandem assemblies. The compressors of a tandem assembly can be manifolded together allowing them to work simultaneously on the same heating or cooling circuit to deliver pressurized refrigerant to the HVAC system. In some manifold configurations, oil used as a lubricant in the HVAC system is equalized between the compressors of the tandem assembly by an oil equalization system, such as piping between each compressor that maintains an equal oil level in the oil sumps. When both compressors of the tandem assembly are operating, the oil equalization system ensures that oil is transferred between the compressors to prevent starving or overfilling of any one compressor, or other problems.
When one compressor of a tandem assembly is turned off and the other is running, however, refrigerant will likely condense in the oil sump of the idle compressor. Collection of liquid refrigerant in the oil sump dilutes the oil available to the idle compressor, and can cause compressor problems and even failures, when the idle compressor is turned back on. What is needed are lubricant management systems and methods that will improve the reliability and efficiency of compressor assemblies, reducing down time for maintenance and repair, and extending the life of the assembly.